Electronic module configured for failure containment and system including same

ABSTRACT

An electronic module. The electronic module includes a chassis, a plurality of capacitors, and a heat sink. The chassis includes a first end and a second end. The first end is opposite the second end. The chassis also includes a first side, a second side, a third side, and a fourth side. The second side is opposite the first side. The third side is connected to at least one of the first and second sides. The fourth side is connected to at least one of the first and second sides, and is opposite the third side. The chassis is fabricated from a material which stops component debris from passing through the sides of the chassis. The capacitors are positioned within the chassis. The heat sink is positioned between the capacitors and the second end.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. Provisional PatentApplication No. 60/818,081, filed on Jun. 30, 2006.

Not Applicable

BACKGROUND

This application discloses an invention that is related, generally andin various embodiments, to an electronic module configured for failurecontainment.

Electronic modules come in a variety of shapes, sizes andconfigurations, and are utilized in a wide range of applications. Forexample, in some applications, the electronic modules form portions of apower supply, accept a three-phase AC input power, and output a singlephase AC voltage. Such electronic modules include internal componentswhich generate a measurable amount of heat, and such heat can affect theperformance of the respective components and the electronic moduleitself.

In many applications, the amount of heat generated causes certaincomponents to fail. For example, it is known for capacitors to fail todue increased temperatures. Such failures can result in an explosion,and debris from the explosion can cause significant damage not only tothe electronic module, but to other devices near the electronic module.

SUMMARY

In one general respect, this application discloses an electronic module.According to various embodiments, the electronic module includes achassis, a plurality of capacitors, and a heat sink. The chassisincludes a first end and a second end. The second end is opposite thefirst end. The chassis also includes a first side, a second side, athird side, and a fourth side. The second side is opposite the firstside. The third side is connected to at least one of the first andsecond sides. The fourth side is connected to at least one of the firstand second sides, and is opposite the third side. The chassis isfabricated from a material which stops component debris from passingthrough the sides of the chassis. The capacitors are positioned withinthe chassis. The heat sink is positioned between the capacitors and thesecond end.

In another general respect, this application discloses a system.According to various embodiments, the system includes a fan and anelectronic module. The electronic module includes a chassis, a pluralityof capacitors, and a heat sink. The chassis includes a first end and asecond end. The second end is opposite the first end. The chassis alsoincludes a first side, a second side, a third side, and a fourth side.The second side is opposite the first side. The third side is connectedto at least one of the first and second sides. The fourth side isconnected to at least one of the first and second sides, and is oppositethe third side. The capacitors are positioned within the chassis. Theheat sink is positioned between the capacitors and the second end, andis positioned such that when the fan generates an airflow, the airflowcarries component debris toward the heat sink.

DESCRIPTION OF DRAWINGS

Various embodiments of the invention are described herein by way ofexample in conjunction with the following figures.

FIG. 1 illustrates various embodiments of an electronic module;

FIG. 2 illustrates various embodiments of the electronic module of FIG.1;

FIG. 3 illustrates various embodiments of the electronic module of FIG.1;

FIG. 4 illustrates various embodiments of the electronic module of FIG.1; and

FIG. 5 illustrates various embodiments of a system which includes theelectronic module of FIG. 1.

DETAILED DESCRIPTION

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to focus on elementsthat are relevant for a clear understanding of the invention, whileeliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not necessarily facilitate a better understanding ofthe invention, a description of such elements is not provided herein.

FIG. 1 and FIG. 2 illustrate various embodiments of an electronic module10. The electronic module 10 may be implemented as any type of modulesuch as, for example, a power cell, a power supply, an inverter, a drivechassis, etc. According to various embodiments, the electronic module 10is implemented as a power cell which accepts three phase AC input powerand outputs a single phase AC voltage. Such a power cell is described inU.S. Pat. No. 5,625,545 (Hammond), and includes an AC-to-DC rectifier, asmoothing circuit, an output DC-to-AC converter, and a control circuit.

The electronic module 10 includes a chassis 12 having a first end 14 anda second end 16 which is opposite the first end 14. The first end 14 maybe considered the “front” of the electronic module 10. The second end 16is opposite the first end 14 and may be considered the “back” of theelectronic module 10. According to various embodiments, the chassis 12may be comprised of several portions connected together (e.g., a top, abottom, and four sides), and one or more portions of the chassis 12 maybe removable. The chassis 12 defines an exterior portion of theelectronic module 10, and encloses various components (e.g., any or allof the following: capacitors, printed circuit boards, heat sink,switching devices, resistors, etc.) of the electronic module 10. Thechassis 12 may be fabricated from any suitable material. For example,according to various embodiments, the chassis 12 is fabricated from aconductive material such as a metal (e.g., galvanized steel). For suchembodiments, the conductive material of the chassis 12 may serve toprovide a low impedance path for arcing faults within the chassis 12 tominimize potential damage caused thereby. The chassis 12 may be of athickness sufficient to stop any debris resulting from a failure of aninternal component of the electronic module 10 from exiting the spaceenclosed by the chassis 12, thereby preventing any collateral damage toother components in the vicinity of the electronic module 10. Inaddition, the chassis 12 may serve to protect internal components of theelectronic module 10 from damage during shipping and handling, and maybe configured in a manner such that the electronic module 10 can beplaced on any of its sides without causing any damage to the componentsof the electronic module 10. Furthermore, as described in more detailhereinbelow, the chassis 12 may also define an air plenum utilized toassist in the forced air cooling of all components within the chassis12.

The chassis 12 also includes a first side 18, a second side 20, a thirdside 22 (see FIG. 3), and a fourth side 24. The first side 18 may beconsidered the “right” side of the chassis 12. The second side 20 isopposite the first side 18, and may be considered the “left” side of thechassis 12. The third side 22 is connected to at least one of the firstand second sides 18, 20, and may be considered the “top” of the chassis12. For purposes of clarity, the electronic module 10 is shown havingthe third side 22 removed in FIG. 1 and FIG. 2. The fourth side 24 isopposite the third side 22, is connected to at least one of the firstand second sides 18, 20, and may be considered the “bottom” of thechassis 12. The sides of the chassis are fabricated from a material(e.g., galvanized steel) which stops component debris from passingtherethrough. As shown in FIG. 1, the first end 14 defines an opening 26proximate the fourth side 24, and also defines one or more openings 28proximate the opening 26. Collectively, the first and second ends 14,16, and the first, second, third, and fourth sides 18, 20, 22, 24 of thechassis 12 enclose substantially the entire electronic module 10.

As shown in FIG. 2, the electronic module 10 includes a plurality of busbars 30 positioned within the chassis 12 proximate the second end 16, aplurality of power plug connectors 32 positioned proximate the secondend 16, and a plurality of resistors 34 positioned proximate the secondend 16. The resistors 34 are electrically connected to capacitors of theelectronic module 10, and function to bleed current from the capacitorswhen power to the electronic module 10 is interrupted or shut down.

The bus bars 30 may be fabricated from any suitable conductive material,and are collectively configured to route power to and from theelectronic module 10. For this embodiment, at least two of the bus bars30 are configured as input bus bars and at least two of the bus bars 30are configured as output bus bars. The number, size and shape of the busbars 30 can vary by application. In general, the respective bus bars 30are sized to accommodate requirements associated with a particularapplication.

According to various embodiments, each power plug connector 32 includesa conductive material and a housing which surrounds the conductivematerial. The conductive material may be fabricated from any suitableconductor such as, for example, copper. The housing may be fabricatedfrom any suitable insulating material such as, for example, a plastic.The housing defines an opening configured to receive a portion of asystem bus when the electronic module 10 is connected to a system bus.The opening surrounds the conductive material, and the conductivematerial defines a smaller opening configured to receive the portion ofthe system bus when the electronic module 10 is connected to the systembus. Thus, the housing and the conductive material collectively definean opening which is sized to receive the portion of the system bus whenthe electronic module 10 is connected to the system bus.

As shown in FIG. 2, the power plug connectors 32 are connected tocorresponding bus bars 30. A given power plug connector 32 may beconnected to a corresponding bus bar 30 in any suitable manner. Forexample, according to various embodiments, the power plug connector 32is mechanically connected to the bus bar 30 via fasteners (e.g., screwsor nuts and bolts) in a manner that places the conductive material indirect contact with the bus bar 30. Thus, the bus bar 30 may also act asa heat sink for the power plug connector 32 connected thereto. The powerplug connector 32 is configured such that it can be connected to the busbar 30 in a manner that the permits some movement of the power plugconnector 32.

According to other embodiments, the power plug connectors may beconfigured in a different manner. For example, according to variousembodiments, a given power plug connector may include a male portion anda separate female portion which collectively function to connect theelectronic module 10 to the system bus. For some embodiments, the maleportion is connected to the corresponding bus bar and the female portionis connected to the system bus. In other embodiments, the male portionis connected to system bus and the female portion is connected to thecorresponding bus bar. In general, for a given application, theparticular configuration of power plug connectors are selected toaccommodate requirements associated with a particular application.

FIG. 3 illustrates a cross-section of the electronic module 10 accordingto various embodiments. As shown in FIG. 3, the electronic module 10also includes a plurality of capacitors 36, a heat sink 38, a firstswitching device 40, a second switching device 42, one or more capacitortrays 44, a control board 46, and a deflector 48. As explained in moredetail hereinbelow, the respective components of the electronic module10 are positioned in a manner which defines various paths for airflowing through the chassis 12. For reasons of clarity, the paths areshown in a single line format in FIG. 3, and include a first path 50, asecond path 52, and a third path 54.

The capacitors 36 are positioned within the chassis 12, and at least oneof the capacitors 36 is proximate the first end 14 of the chassis 12.According to various embodiments, the capacitors 36 are electrolyticcapacitors. The heat sink 38 is positioned between the capacitors 36 andthe bus bars 30. The heat sink 38 may be fabricated from any suitablethermally conductive material. For example, according to variousembodiments, the heat sink 38 is fabricated from a metal (e.g.,lightweight aluminum) and incorporates a mechanically swagged hollow findesign. The fins are spaced apart from one another, and operate todissipate heat and stop component debris from passing therebetween. Thefirst switching device 40 is positioned between the heat sink 38 and thethird side 22 of the chassis 12. The second switching device 42 ispositioned between the heat sink 38 and the third side 22 of the chassis12, as well as between the first switching device 40 and the second end16 of the chassis 12. According to various embodiments, the first andsecond switching devices 40, 42 are implemented as insulated gatebipolar transistor modules and are configured to operate in parallel asone device.

Each capacitor tray 44 is positioned within the chassis 12 between thecapacitors 36 and the fourth side 24 of the chassis 12, and may befabricated from any suitable material (e.g., a plastic). The capacitortray 44 functions to help support the capacitors 36 in a position awayfrom the fourth side 24 of the chassis 12. The capacitor tray alsofunctions to stop at least a portion of component debris from passingtherethrough. According to various embodiments, a given capacitor tray44 defines one or more openings 56 (see FIG. 4) aligned withcorresponding capacitors 36, wherein each opening 56 is sized smallerthan a circumference of the corresponding capacitor 36.

The control board 46 is positioned between the capacitor tray 44 and thefourth side 24 of the chassis 12, includes a number of components, andis configured to monitor and/or control the operation of the electronicmodule 10. For example, according to various embodiments, the controlboard 46 is configured to control the operation of first and secondswitching devices 40, 42, control fiber optic communications from theelectronic module 10, etc. As shown in FIG. 4, according to variousembodiments, the portion of the fourth side 24 of the chassis 12 thatthe control board 46 is connected to may be hingedly connected to thechassis 12 to allow for easy access to the control board 46.

Returning to FIG. 3, the deflector 48 is positioned between thecapacitors 36 and the second end 16 of the chassis 12, as well asbetween the heat sink 34 and the fourth side 24 of the chassis 12. Thedeflector 48 may be fabricated from any suitable material. According tovarious embodiments, the deflector is fabricated from a material (e.g.,a metal, a plastic, etc.) having a thickness sufficient to stop at leastsome of the debris resulting from a failure of an internal component ofthe electronic module 10 from passing through the deflector 48. Thedeflector 48 is configured to redirect a portion of air approaching thedeflector 48 toward the heat sink 38. Although the deflector 48 is shownin FIG. 3 as having a distinct bend, the functionality of the deflector48 may be realized with other configurations. As shown in FIG. 3, thedeflector 48 defines an opening 58 therethrough. The opening 58 allowsair flowing towards the deflector 48 to pass through the opening 58toward the resistors 34. According to various embodiments, the opening58 is aligned with the resistors 34.

FIG. 5 illustrates various embodiments of a system 60. The system 60 maybe utilized in a variety of applications. For example, the system 60 maybe utilized as a power supply. The system 60 includes the electronicmodule 10 of FIG. 1. According to various embodiments, the system 60 mayinclude any number of electronic modules 10. For example, according tovarious embodiments, the system 60 may include anywhere from one totwenty-four electronic modules 10. For purposes of clarity only threeelectronic modules 10 are shown in FIG. 5.

The system 60 also includes a fan 62. The fan 62 may be any type of fansuitable for moving air. For example, according to various embodiments,the fan 62 is a backward inclined centrifugal fan. Additionally, the fan62 may be arranged in any suitable configuration with respect to theelectronic modules 10. For example, the fan 62 may be arranged in adraw-thru configuration as shown in FIG. 5. According to otherembodiments, the fan 62 may be arranged in a different configuration(e.g., blow-thru). The system 60 may include any number of fans 62. Forexample, according to various embodiments, the system 60 includes twofans 62. For such embodiments, one of the two fans 62 may be utilized asa redundant fan.

In operation, the fan 62 serves to generate an airflow 64 through therespective electronic modules 10 of the system 60. A first portion ofthe airflow enters the chassis 12 at the one or more openings 28 definedby the first end 14 and proceeds along the first path 50. As the firstportion of the airflow advances along the first path 50 toward thesecond end 16, the airflow circulates around and comes in contact withthe capacitors 36, thereby serving to cool the capacitors 36. Afterpassing the volume proximate the capacitors 36, the first portion of theairflow comes in contact with the heat sink 38 while circulating aroundand between the fins thereof, thereby serving to dissipate heat from theheat sink 38. Concurrent therewith, the first portion of the airflowalso sequentially comes in contact with the first switching device 40and the second switching device 42, thereby serving to cool theswitching devices 40, 42. After passing the volume occupied by the heatsink 38 and the first and second switching devices 40, 42, the firstportion of the airflow circulates around and comes in contact with thebus bars 30 and the power plug connectors 32 before exiting the secondend 16 of the chassis 12, thereby serving to cool the bus bars 30 andthe power plug connectors 32.

Concurrent with the flow of the first portion of the airflow through thechassis 12, a second portion of airflow enters the chassis 12 at theopening 26 defined by the first end 14 and proceeds along the secondpath 52. As the second portion of the airflow advances along the secondpath 52 toward the second end 16, the airflow circulates around andcomes in contact with the capacitor tray 44, and also comes in contactwith portions of the capacitors 36 via the openings 56 defined by thecapacitor tray 44, thereby serving to cool the capacitors 36 and thecapacitor tray 44. Concurrent therewith, the second portion of theairflow also circulates around and comes in contact with the controlboard 46, thereby serving to cool the control board 46.

After passing the volume occupied by the capacitor tray 44 and thecontrol board 46, the second portion of the airflow approaches thedeflector 48. A portion of the second portion of the airflow passesthrough the opening 58 defined by the deflector 48, then circulatesaround and comes in contact with the resistors 34, thereby serving tocool the resistors 34. After passing by the volume occupied by theresistors 34, the portion of the second portion of the airflow may alsocirculate around and come in contact with the bus bars 30 and the powerplug connectors 32 before exiting at the second end 16 of the chassis12, thereby serving to cool the bus bars 30 and the power plugconnectors 32.

When the remaining portion of the second portion of the airflow comesnear or in contact with the deflector 48, the remaining portion isdeflected along the third path 54 toward the heat sink 38 and the secondswitching device 42. The remaining portion of the second portion of theairflow comes in contact with the heat sink 38 while circulating aroundand between the fins thereof, thereby serving to dissipate heat from theheat sink 38. The remaining portion of the second portion of the airflowalso comes in contact with the second switching device 42, therebyserving to further cool the switching device 42. The additional coolingof the second switching device 42 by the remaining portion of the secondportion of the airflow serves to maintain both of the switching devices40, 42 at approximately the same temperature. The remaining portion ofthe second portion of the airflow effectively merges with the firstportion of the airflow (i.e., the first and third paths 50, 54 combinewith one another) and circulates around and comes in contact with thebus bars 30 and the power plug connectors 32 before exiting at thesecond end of the chassis 12.

The above-described airflows and the configuration of the electronicmodule 10 also function to contain any failures which occur within thechassis 12. In general, capacitors are known to overheat and fail in theabsence of a sufficient amount of airflow. Some such failures result inthe explosion of the capacitor. As the chassis 12 is fabricated from asufficient thickness of a suitably strong material (e.g., galvanizedsteel) and encloses substantially the entire electronic module 10, anyof the debris resulting from such an explosion which comes in contactwith the chassis 12 is not likely to pass through the chassis 12 (e.g.,through one of the sides of the chassis). Similarly, any debrisresulting from the failure of other components within the chassis 12 ofthe electronic module 10 (e.g., the control board, the switchingdevices, the resistors, etc.) which comes in contact with the chassis 12also is not likely to pass through the chassis 12. Thus, when a failureoccurs in a given electronic module 10, the construction of the chassis12 operates to reduce the chance of the failure damaging any adjacentelectronic modules 10.

With the capacitors 36 positioned where they are the first components tocome in contact with the first portion of the airflow, the capacitors 36are exposed to the coolest air of the first portion of the airflow,thereby reducing the chance of overheating. Also, by having a portion ofeach capacitor exposed to the second portion of the airflow via theopenings 56 in the capacitor tray 44, such capacitor portions are alsoexposed to the coolest air of the second portion of the airflow, therebyreducing the chance of overheating at the respective portions mostlikely to become overheated. In the event that one of the capacitors 36does explode, the relatively high volume of airflow will carry thecapacitor debris toward the heat sink 38, and the spaced-apart fins ofthe heat sink 38 will stop a significant portion of such debris frompassing therebetween. Any debris which is not blocked by the heat sink38 will be relatively small and cool, and may nonetheless be blockedfrom exiting the chassis 12 by the second end 16 of the chassis 12.

By also positioning the control board 46 to receive the coolest air ofthe second portion of the airflow, the potential for failure of thecontrol board 46 is significantly reduced. In the event that one of thecomponents of the control board 46 does explode, the relatively highvolume of airflow will carry the capacitor debris toward the heat sink38 via the deflector 48, where a significant portion of such debris willbe blocked from advancing further. Any debris which is not blocked bythe heat sink 38 may nonetheless be blocked from exiting the chassis 12by the second end 16 of the chassis 12.

As the first and second switching devices 40, 42 may be operated inparallel as a single device, it is advantageous to keep the twoswitching devices 40, 42 at approximately the same temperature. With thefirst switching device 40 positioned before the second switching device42 along the first airflow path 50, the heat transferred from the firstswitching device 40 to the first portion of airflow results in thesecond switching device 42 being exposed to somewhat warmer air from thefirst portion of airflow than the first switching device 40 is. Topromote similar cooling of the first and second switching devices 40,42, the deflector 48 is positioned such that second switching device 42is also exposed to the airflow from the third airflow path 54.

As air within the chassis 12 may become ionized, the flow of air throughthe chassis 12 reduces the likelihood of such ionization occurring,thereby reducing the time of, and associated damage resulting from, anelectric arc within the chassis 12.

While several embodiments of the invention have been described herein byway of example, those skilled in the art will appreciate that variousmodifications, alterations, and adaptions to the described embodimentsmay be realized without departing from the spirit and scope of theinvention defined by the appended claims.

1. An electronic module, comprising: a chassis having a first end and asecond end opposite the first end, wherein the chassis comprises: afirst side; a second side opposite the first side; a third sideconnected to at least one of the first and second sides; and a fourthside connected to at least one of the first and second sides, whereinthe fourth side is opposite the third side; a plurality of capacitorspositioned within the chassis; and a heat sink positioned between thecapacitors and the second end, wherein the chassis is fabricated from amaterial which stops component debris from passing through the sides ofthe chassis.
 2. The electronic module of claim 1, wherein the materialis a metal.
 3. The electronic module of claim 2, wherein the metal isgalvanized steel.
 4. The electronic module of claim 4, wherein a portionof one of the sides is hingedly connected to the chassis.
 5. Theelectronic module of claim 1, wherein at least one of the capacitors isan electrolytic capacitor.
 6. The electronic module of claim 1, whereinthe heat sink is fabricated from a thermally conductive material.
 7. Theelectronic module of claim 6, wherein the thermally conductive materialis aluminum.
 8. The electronic module of claim 1, wherein the heat sinkcomprises spaced-apart fins which stop at least some of the componentdebris from passing therebetween.
 9. The electronic module of claim 1,further comprising a capacitor tray positioned between the capacitorsand one of the sides of the chassis, wherein the capacitor tray isfabricated from a material which stops at least some of the componentdebris from passing therethrough.
 10. The electronic module of claim 9,further comprising a control board positioned between the capacitor trayand one of the sides of the chassis.
 11. The electronic module of claim1, further comprising a deflector positioned between the capacitors andthe second end, wherein the deflector is fabricated from a materialwhich stops at least some of the component debris from passingtherethrough.
 12. The electronic module of claim 1, further comprising afirst switching device positioned between the heat sink and one of thesides of the chassis.
 13. The electronic module of claim 12, furthercomprising a second switching device positioned between the heat sinkand the one of the sides of the chassis.
 14. The electronic module ofclaim 1, further comprising a resistor positioned between the deflectorand the second end.
 15. A system, comprising: a fan; and an electronicmodule, wherein the electronic module comprises: a chassis having afirst end and a second end opposite the first end, wherein the chassiscomprises: a first side; a second side opposite the first side; a thirdside connected to at least one of the first and second sides; and afourth side connected to at least one of the first and second sides,wherein the fourth side is opposite the third side; a plurality ofcapacitors positioned within the chassis; and a heat sink positionedbetween the capacitors and the second end, wherein the heat sink ispositioned such that when the fan generates an airflow, the airflowcarries component debris toward the heat sink.
 16. The system of claim15, wherein the chassis is fabricated from a material which stopscomponent debris from passing through the sides thereof.
 17. The systemof claim 15, wherein the heat sink comprises spaced-apart fins whichstop at least some of the component debris from passing therebetween.18. The system of claim 15, wherein the electronic module furthercomprises a capacitor tray positioned between the capacitors and one ofthe sides of the chassis, wherein the capacitor tray is fabricated froma material which stops at least some of the component debris frompassing therethrough.
 19. The system of claim 18, wherein the electronicmodule further comprises a control board positioned between thecapacitor tray and one of the sides of the chassis.
 20. The system ofclaim 15, wherein the electronic module further comprises a deflectorpositioned between the capacitors and the second end, wherein thedeflector is fabricated from a material which stops at least some of thecomponent debris from passing therethrough.